The bottom line is, God's presence changes everything and the key to His presence is continual, prayer, praise and worship. It's possible if churches in a community cooperate together.
Their testimony begins with supernatural signs and wonders just like we've seen happen for years! In their case 225 lighting strikes. The first newsletter (3rd & 4th pic) below share's their testimony. Just scroll few a few and you can see the long term impact it's had in the 7 mountains of society in Eugene and Springfield Oregon.
Pastors say: "we remember the answer to prayer that One Church - One Day is in itself. Pastors are grateful strategic teams are providing focused prayers, making it possible for churches to pray together 24/7. They say One Church One Day is "contributing to an overall movement of the Church to be outward focused."
City Manager says: (2nd pic) "what we see are answers to prayer, not just serendipitous acts."